This invention relates to improvements in kinetic energy rod warheads.
Destroying missiles, aircraft, re-entry vehicles and other targets falls into three primary classifications: xe2x80x9chit-to-killxe2x80x9d vehicles, blast fragmentation warheads, and kinetic energy rod warheads.
xe2x80x9cHit-to-killxe2x80x9d vehicles are typically launched into a position proximate a re-entry vehicle or other target via a missile such as the Patriot, Trident or MX missile. The kill vehicle is navigable and designed to strike the re-entry vehicle to render it inoperable. Countermeasures, however, can be used to avoid the xe2x80x9chit-to-killxe2x80x9d vehicle. Moreover, biological warfare bomblets and chemical warfare submunition payloads are carried by some xe2x80x9chit-to-killxe2x80x9d threats and one or more of these bomblets or chemical submunition payloads can survive and cause heavy casualties even if the xe2x80x9chit-to-killxe2x80x9d vehicle accurately strikes the target.
Blast fragmentation type warheads are designed to be carried by existing missiles. Blast fragmentation type warheads, unlike xe2x80x9chit-to-killxe2x80x9d vehicles, are not navigable. Instead, when the missile carrier reaches a position close to an enemy missile or other target, a pre-made band of metal on the warhead is detonated and the pieces of metal are accelerated with high velocity and strike the target. The fragments, however, are not always effective at destroying the target and, again, biological bomblets and/or chemical submunition payloads survive and cause heavy casualties.
The textbooks by the inventor hereof, R. Lloyd, xe2x80x9cConventional Warhead Systems Physics and Engineering Design,xe2x80x9d Progress in Astronautics and Aeronautics (AIAA) Book Series, Vol. 179, ISBN 1-56347-255-4, 1998, and xe2x80x9cPhysics of Direct Hit and Near Miss Warhead Technologyxe2x80x9d, Volume 194, ISBN 1-56347-473-5, incorporated herein by this reference, provide additional details concerning xe2x80x9chit-to-killxe2x80x9d vehicles and blast fragmentation type warheads. Chapter 5 and Chapter 3 of these textbooks propose a kinetic energy rod warhead.
The two primary advantages of a kinetic energy rod warhead is that 1) it does not rely on precise navigation as is the case with xe2x80x9chit-to-killxe2x80x9d vehicles and 2) it provides better penetration then blast fragmentation type warheads.
To date, however, kinetic energy rod warheads have not been widely accepted nor have they yet been deployed or fully designed. The primary components associated with a theoretical kinetic energy rod warhead is a hull, a projectile core or bay in the hull including a number of individual lengthy cylindrical projectiles, and an explosive charge in the hull about the projectile bay with sympathetic explosive shields. When the explosive charge is detonated, the projectiles are deployed.
The projectiles, however, may tend to break and/or tumble in their deployment. Still other projectiles may approach the target at such a high obliquity angle that they do not effectively penetrate the target. See xe2x80x9cAligned Rod Lethality Enhanced Concept for Kill Vehicles,xe2x80x9d R. Lloyd xe2x80x9cAligned Rod Lethality Enhancement Concept For Kill Vehiclesxe2x80x9d 10th AIAA/BMDD TECHNOLOGY CONF., July 23-26, Williamsburg, Va., 2001 incorporated herein by this reference. To date, the focus has been on long cylindrical flat ended projectiles with a high length to diameter ratio. This shape for the projectiles, however, is not optimized from the standpoint of strength, weight, packaging efficiency, penetrability, and lethality.
It is therefore an object of this invention to provide an improved kinetic energy rod warhead.
It is a further object of this invention to provide a higher lethality kinetic energy rod warhead.
It is a further object of this invention to provide a kinetic energy rod warhead with penetrators optimized in shape to improve on the strength, weight, packaging efficiency, penetrability, and lethality of prior art cylindrical cross section projectiles.
It is a further object of this invention to provide such a kinetic energy rod warhead which is capable of aligning and selectively directing the projectiles at a target.
It is a further object of this invention to provide such a kinetic energy rod warhead which prevents the projectiles from breaking when they are deployed.
It is a further object of this invention to provide such a kinetic energy rod warhead which prevents the projectiles from tumbling when they are deployed.
It is a further object of this invention to provide such a kinetic energy rod warhead which insures the projectiles approach the target at a better penetration angle.
It is a further object of this invention to provide such a kinetic energy rod warhead which can be deployed as part of a missile or as part of a xe2x80x9chit-to-killxe2x80x9d vehicle.
It is a further object of this invention to provide such a kinetic energy rod warhead with projectile shapes which have a better chance of penetrating a target.
It is a further object of this invention to provide such a kinetic energy rod warhead with projectile shapes which can be packed more densely.
It is a further object of this invention to provide such a kinetic energy rod warhead which has a better chance of destroying all of the bomblets and chemical submunition payloads of a target to thereby better prevent casualties.
The invention results from the realization that a higher lethality and lower weight kinetic energy rod warhead can be effected by the inclusion of penetrators having non-cylindrical cross sectional shapes and/or pointed ends and which can be packaged more efficiently. This invention results from the further realization that a higher lethality kinetic energy rod warhead can be effected by the inclusion of means for aligning the individual projectiles when they are deployed to prevent the projectiles from tumbling and to provide a better penetration angle by selectively directing the projectiles at the target.
This invention features a kinetic energy rod warhead comprising a hull, a core in the hull including a plurality of individual penetrators, and an explosive charge in the hull about the core. The penetrators typically have a non-cylindrical cross-section for improved strength, weight, packaging efficiency, penetrability, and/or lethality. In one example, the penetrators have opposing ends at least one of which is pointed. In another example, the penetrators have a tri-star cross-section including three lateral petals spaced 120xc2x0 apart. Another type of penetrator has a cruciform cross-section including a plurality of petals. There may be four petals each spaced 90xc2x0 apart. In one example, the petals have a constant width and opposing converging surfaces. In another example, the penetrators have a star cross-section including a number of petals and the star cross-section penetrators have opposing ends at least one of which is pointed or wedge-shaped.
Further included may be means for aligning the individual penetrators when the explosive charge deploys the penetrators. In one example, the means for aligning includes a plurality of detonators spaced along the explosive charge configured to prevent sweepling shock waves at the interface of the core and the explosive charge to prevent tumbling of the penetrators. In another example, the means for aligning includes a body in the core with orifices therein, and the penetrators are disposed in the orifices of the body. In another example, the means for aligning includes a flux compression generator which generates a magnetic alignment field to align the penetrators. Typically, there are two flux compression generators, one on each end of the projectile core and each flux compression generator includes a magnetic core element, a number of coils about the magnetic core element, and an explosive for imploding the magnetic core element.
Typically, the projectiles are made of a low density material. The hull is typically the skin of a missile or a portion of a xe2x80x9chit-to-killxe2x80x9d vehicle. In some embodiments, the explosive charge is outside the core; but in other examples, the explosive charge is inside the core. A low density material buffer material may be disposed between the core and the explosive charge. Typically, the penetrators are lengthy metallic (e.g., tungsten) members.
In the preferred embodiment, the explosive charge is divided into sections and there are shields between each explosive charge section extending between the hull and the projectile core. The shields may be made of a composite material, e.g., steel sandwiched between lexan layers. In another embodiment, the core is divided into a plurality of bays, the explosive charge is divided into a plurality of sections and there is at least one detonator per section for selectively detonating the charge sections to aim the penetrators in a specific direction and to control the spread pattern of the penetrators. Each explosive charge section may be wedged-shaped having a proximal surface abutting the projectile core and a distal surface. The distal surface is typically tapered to reduce weight.
Another kinetic energy rod warhead in accordance with this invention features a hull, a projectile core in the hull including a plurality of individual penetrators, and an explosive charge in the hull about the core. The penetrators have opposing ends at least one of which is pointed and/or the penetrators have a non-cylindrical cross section and opposing ends at least one of which is either non-cylindrical in cross section or, if cylindrical in cross section, non-flat.
Another kinetic energy rod warhead in accordance with this invention features a hull, a core in the hull including a plurality of individual tri-star cross section penetrators, and an explosive charge in the hull about the core.